Prevalence of latent tuberculosis infection and associated risk factors among 1557 nursing students in a context of low endemicity

Mycobacterium tuberculosis latent infection in healthcare students: systematic review of prevalence

OBJECTIVE

The aim of this study was to synthesize the evidence on the prevalence of latent Mycobacterium tuberculosis infection (LTBI) among undergraduate health care students.

METHODS

A systematic review of prevalence with meta-analysis was conducted. Prospective and retrospective cohorts and cross-sectional studies involving probable exposure to M. tuberculosis during undergraduate education, along with the tuberculin skin test (TST) or interferon-γ release assay (IGRA) for investigation of latent tuberculosis were searched. Searches were conducted in MEDLINE, CINAHL, EMBASE, LILACS, Scopus, and Web of Science databases. Independent reviewers were responsible for the selection and inclusion of studies. Data were extracted, critically appraised, and synthesized using the JBI approach. PRISMA was used to report the study.

RESULTS

Twenty-two studies were analyzed. The overall prevalence in healthcare undergraduate students was 12.53%.

CONCLUSION

The prevalence of LTBI in undergraduate health students was high for such a highly educated population. Screening with TST and/or IGRA and chemoprophylaxis, when necessary, should be provided to undergraduate health students when in contact with respiratory symptomatic patients.

Prevalence and risk factors of latent tuberculosis infection among college students: a systematic review and meta-analysis

OBJECTIVES

College students are at increased risk of tuberculosis (TB), which increases their likelihood of developing latent tuberculosis infections (LTBI). This study aimed to estimate the pooled prevalence of LTBI and identify its risk factors.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

We searched PubMed, Embase, Scopus, Web of Science, CNKI, Wanfang and CBM databases (10 March 2022) for studies published in any language. The pooled prevalence of LTBI was estimated using random effects methods. Factors associated with LTBI were evaluated by determining standardised mean difference (SMD) with 95% confidence interval (CI). All analyses were performed using the Stata 15.1.

RESULTS

A total of 50 studies from 18 countries were included, with 44 tuberculin skin test (n = 623,732) and 19 interferon gamma release assay (n = 38,266) estimates. The prevalence of a positive tuberculin skin test was 20% (95% CI: 17-23%), and the prevalence of a positive interferon gamma release assay was 9% (95% CI: 7%-11%) among college students. Older age (SMD: 1.67, 95% CI: 1.31-2.13), no Bacillus Calmette-Guérin vaccination/scar (SMD: 1.51, 95% CI: 1.06-2.16), contact with TB cases (SMD: 1.34, 95% CI: 1.11-1.62), clinical training (SMD: 1.93, 95% CI: 1.65-2.26) and overweight/obesity (SMD: 1.17, 95% CI: 1.06-1.30) were associated with a higher prevalence of LTBI. Sex was not associated with LTBI prevalence.

CONCLUSION

College students have an increased risk of LTBI, although it varies by geographical area. This meta-analysis provides evidence of risk factors for LTBI in college students. Infection control measures should be conducted for college students with LTBI.

Latent Tuberculosis Infection among Healthcare Students and Postgraduates in a Mediterranean Italian Area: What Correlation with Work Exposure?

Background: Tuberculosis screening is part of the standard protocol for evaluating the risk of infection in healthcare workers. The aim of this study was to evaluate the prevalence of latent tuberculosis infection (LTBI) among students attending various healthcare profession degree courses and postgraduate medical courses at the School of Medicine of the University of Palermo, Italy, and assess the possible professional origin of infection. Methods: In total, 2946 students (2082 undergraduates and 864 postgraduates) took part in a screening program for LTBI between January 2014 to April 2019 using the tuberculin skin test (TST). Students with a positive TST result underwent a Quantiferon-TB test (QFT). Results: Among the 2082 undergraduates, 23 (1.1%) had a positive TST; the result was confirmed with QFT for 13 (0.62%) of them. Among the 864 postgraduate students, 24 (2.78%) had a positive TST and only 18 (2.08%) showed a positive QTF. Latent tuberculosis infections were significantly more frequent among postgraduates than undergraduates (2.08% > 0.62%, p < 0.0001). There was a higher number of subjects previously vaccinated for TB (18.87% > 0.24%, p < 0.0001), and of vaccinated subjects found positive for TST and QTF (66.67% > 7.69%, p = 0.001) in the postgraduate group. Conclusion: Latent TB is relatively low among medical school students in our geographic area. Nevertheless, this infectious disease must be regarded as a re-emerging biohazard for which preventive strategies are required to limit the risk of infection, especially among exposed workers.

Prevalence and associated risk factors of latent tuberculosis infection among undergraduate and postgraduate dental students: A retrospective study

To estimate the prevalence of latent tuberculosis (TB) infection (LTBI) in Italian dental students exposed to the same occupational risks as dental health care personnel and to evaluate potential risk factors, a cross-sectional study was conducted on undergraduate and postgraduate students. After clinical evaluation, students were given a tuberculin skin test; in those found positive, an interferon-γ release assay (IGRA) was conducted. Of the 281 students enrolled, 10 were only TST positive; 8 were TST or/and IGRA positive. We found that participants testing positive at TST and/or IGRA, a group in which the risk of false LTBI positives is minimal, were older and had been studying longer. Although the prevalence of LTBI among dental students in our study was low, a risk of acquiring a work-related infection exists even in a country with a low incidence of TB. Thus, dental students should be screened to catch LTBI early on.

Evaluation of Tuberculin Skin Test Positivity and Early Tuberculin Conversion among Medical Intern Trainees in Tunisia

BACKGROUND

As healthcare workers (HCWs), medical trainees are at a high-risk for acquisition of tuberculosis (TB) infection and disease. To our knowledge, there are no published data about TB infection among medical trainees in Tunisia.To determine the tuberculin skin test (TST) positivity and tuberculin conversion among a group of medical trainees in different departments at our institution.

MATERIALS AND METHODS

We performed a prospective study using the TST. The study was conducted in two steps: 1) an initial TST survey and 2) an evaluation of the TST conversion rates.

RESULTS

Among 114 participants, the TST was positive (≥10 mm) in 26.3% and negative (<5 mm) in 57%. The conversion rate of TST was 4%, which was only observed among the trainees assigned to the pulmonary departments. The significant predictor variables of TST positivity were a history of nosocomial TB exposure and training in a high-risk area.

CONCLUSION

Despite the small number of participants, the high TB conversion rate among the trainees is alarming. This population represents an important target group for a latent tuberculosis infection screening program in countries with limited resources such as Tunisia.

Prevalence of latent tuberculosis infection in healthcare workers at a hospital in Naples, Italy, a low-incidence country

Background

Healthcare workers (HCWs) are at higher risk than the general population of contracting tuberculosis (TB). Moreover, although subjects with latent TB infection (LTBI) are asymptomatic and are not infectious, they may eventually develop active disease. Thus, a fundamental tool of TB control programs for HCWs is the screening and treatment of LTBI.

Methods

From January 2014 to January 2015, hospital personnel at Azienda Ospedaliera Universitaria, Naples, Italy, were screened for TB. To this end, a tuberculin skin test (TST) was administered as an initial examination, unless when contraindicated, in which case the QuantiFERON® TB-Gold (QFT) assay was performed. Moreover, QFT was carried out on all TST-positive cases to confirm the initial result.

Results

Of 628 personnel asked to participate, 28 (4.5%) denied consent, 533 were administered TST as the baseline examination, and 67 were tested only with QFT. In the TST group, 73 (13.2%) individuals were found positive, 418 (78.4%) were negative, and 42 (7.9%) were absent for the reading window; QFT confirmed the result in 39 (53.4%) TST-positive individuals. In the QFT-only group, 44 (65.7%) individuals were found positive. All TST- and/or QFT-positive subjects were referred for chest X-ray and examination by an infectious diseases specialist. None were found to have active TB, and were thus diagnosed with LTBI.

Conclusions

Although Italy is a low-incidence country regarding TB, our findings suggest that the prevalence of LTBI in HCWs may be relatively high. As a result, active screening for TB and LTBI is needed for these workers.

Electronic supplementary material

The online version of this article (doi:10.1186/s12995-016-0141-6) contains supplementary material, which is available to authorized users.

Prevalence and predictors of latent tuberculosis infection among Italian State Policemen engaged in assistance to migrants: a national cross-sectional study

OBJECTIVES

Better knowledge about tuberculosis (TB) and latent TB infection (LTBI) epidemiology is a crucial step for the development of effective strategies towards the control and elimination of this deadliest and persistent health threat. No study has investigated LTBI epidemiology in policemen who act as an interface with cross-border migrants.

METHODS

A survey to measure the LTBI prevalence and assess the demographic, professional and clinical features potentially associated with tuberculin skin test (TST) positivity was performed in Italian State Police (ISP) employees engaged, even occasionally, in relief activities, hospitality, photographical identification, escorting and accompanying of migrants, regardless of contact with active TB cases. Variables potentially associated with TST positivity were evaluated with univariate and multivariate analysis.

RESULTS

From September to December 2014, 4225 ISP workers underwent TST screening and completed the questionnaire for data collection, according to study procedures. The TST was positive in 9.9% of individuals: no active TB cases were registered among the entire study population. Age, previous BCG vaccination and work category resulted independently associated with TST positivity.

CONCLUSIONS

This is the first study providing updated data about LTBI epidemiology among ISP employees engaged in assistance to migrants and furnish preliminary evidence of possible associations between TST positivity and different conditions that need to be deeply investigated with prospective studies.

Vaccination against hepatitis b virus: are Italian medical students sufficiently protected after the public vaccination programme?

Background

The development of a vaccine against hepatitis B virus (HBV) has been a major achievement in terms of prevention of HBV infection. For the present study, we analysed the long-term immunogenicity and effectiveness of HBV vaccination among healthcare students with different working seniorities.

Methods

A cross-sectional study of undergraduate and postgraduate students attending the Medical School of the Second University of Naples was conducted between September 2012 and December 2014. HBV serum markers were determined and multivariate logistic regression analysis was used to identify factors associated with the level of long-term immunogenicity.

Results

Of the 2,932 subjects evaluated, only 33 (1.1 %) declared no history of vaccination. All vaccinated subjects were HBsAg/anti-HBc negative, 459 of which had an anti-HBs titre <10 IU/L. The latter were younger, more likely to be attending a healthcare profession school (i.e., dental hygienists, nursing, paediatric nursing, radiography and midwifery) than a medical school (at either undergraduate or postgraduate level) and more likely to have been vaccinated in infancy.

Conclusion

The results of this study suggest that assessment of HBV serum markers in workers potentially exposed to hospital infections is useful to identify small numbers of unvaccinated subjects or vaccinated subjects with low antibody titre, all of whom should be referred to a booster series of vaccinations.